Some electronic devices such as mobile telephones and personal digital assistants (PDAs) are provided with a touch panel that receives user input by touch. Such an electronic device allows the user to operate it by directly touching the display screen, thereby providing improved operability.
If, for example, a capacitive touch panel is touched when it is wet with water, points where the user does not touch may be regarded as touched. As a result, user's intended operation may not be performed, which decreases the operability.